Código HTML:
<table> <tr> <td>CARGA</td> <td> <select onChange = 'carga.value = this.value' name='barco_carga'> <option value='empty'></option> <option value='[500 Tons]'>barco 1</option> <option value='[1000 Tons]'>barco 2</option> </select> </td> </tr> <tr> <td>max. load</td> <td><input type="text" name="carga" readonly value="[0 Tons]"></td> </tr> </table>